The present invention relates generally to ice making systems for use in a freezer environment, and in particular to ice level sensing systems for use with an ice maker.
Appliances such as refrigerators/freezers may include ice makers that produce ice for discharge into an ice storage bin within the freezer compartment of the appliance. Generally, a mechanical lever arm coupled to the ice maker, that extends towards a bottom of the ice storage bin, controls the production of ice from the ice maker. As ice fills the ice storage bin, the mechanical lever arm is pushed upwards by the ice towards a substantially horizontal orientation relative to the ice storage bin. As long as the mechanical lever extends downwards towards a bottom of the ice storage bin (e.g. the “on” position) the ice maker will produce ice for discharge into the ice storage bin. As the storage bin fills up with ice, the ice causes the mechanical lever arm to pivot relative to the ice maker such that when the mechanical lever arm pivots to a predetermined position (e.g. the “off” position) the ice maker will cease producing ice. Generally, the “off” position corresponds to the ice reaching the top of the ice storage bin.
The moving parts of the mechanical lever arm are subject to freezing, and once frozen, the mechanical lever arm may not function properly for turning off the ice maker when the ice storage bin is full. Because the mechanical arm extends into the ice storage bin, movement of the ice storage bin can be difficult. Movement of the ice storage bin can also cause the displacement of ice from the storage since the arm extends into the ice storage bin.
Some ice level sensing systems use photoelectric or optical sensing devices to control the production of ice. These optical sensing devices will generally include a transmitter and receiver disposed on opposite side of the ice storage bin and the light beam is transmitted across the ice storage bin in one direction. As the ice storage bin fills up, the ice can interrupt the beam from passing from the transmitter to the receiver. This causes the ice maker to turn off and the production of ice ceases. Some of these optical sensing systems are located or extend through the ice storage bins. This requires precise positioning of the ice storage bin relative to the ice maker and relative movement between the optical sensing system and the ice storage bin needs to be prevented. Other optical sensing systems are mounted to a wall of the appliance, which can for allow movement between the ice storage bin and the optical sensing system, such as when the ice storage bin is disposed on a door of the appliance. However, when the door is opened, the ice storage bin moves away from the optical sensing system and the ice storage bin and/or the ice within the ice storage bin can no longer block the light beam of the optical sensing system to turn the ice maker off. As such, ice may be discharged by the ice maker even when the ice storage bin is not disposed in a position to catch the discharged ice.
It would be advantageous to be able to sense a level of ice within an ice storage bin while allowing relative movement between the ice storage bin and the ice sensing system, as well as prevent unwanted discharge of ice by an ice maker when the ice storage bin is not properly positioned or away from the ice maker.